Process for preparing detergent compositions



United States Patent 3,328,305 PROCESS FOR PREPARING DETERGENTCOMPOSITIONS Vincent Lamherti, Upper Saddle River, NJ., assignor toLever Brothers Company, New Yorlt, N.Y., a corporation of Maine NoDrawing. Filed Feb. 16, 1966, Ser. No. 527,727 15 Claims. (Cl. 25289)The present invention relates to an improvement in the preparation ofdetergent compositions.

This application is a continuation-in-part of application, Ser. No.757,202, filed Aug. 26, 1958, now abandoned, and application Ser. No.175,812 filed Feb. 26, 1962, now abandoned.

Cellulose ethers are frequently employed in both dry and liquiddetergent compositions as soil suspending agents. The incorporation ofcellulose ethers in liquid detergent compositions presents aconsiderable problem in that these compounds are not readily soluble ordispersible in water. Thus, when a cellulose ether is added to water atroom temperature to effect hydration thereof, lumps of cellulosic gelare formed which are extremely difficult to dissolve or disperse inwater.

Heretofore, the formation of aqueous dispersions of cellulose ethers hasbeen affected by one of several methods. For example the cellulosiccompounds may be dispersed by first mixing them thoroughly with a minoramount of hot water and allowing them to wet out for a short time. Amajor amount of water is then added either as cold water or ice and theaqueous slurry stirred until a smooth uniform dispersion of thecellulosics is obtained. This so-called hot water method, the principalmethod used heretofore for dispersing cellulose ethers, is costly andtime consuming because of the necessity for heating and cooling thewater.

Another method which has been employed heretofore involves the use ofwetting agents which are miscible with water, such as methyl alcohol,ethyl alcohol, and glycerol. In this process, the cellulosic compoundsare wetted with one of these water-miscible wetting agents to yield aslurry which is subsequently added to a major portion of cold water.Stirring of the alcoholic aqueous slurry produces a uniform dispersionof the cellulosic compounds.

It is an object of this invention to overcome the difficultiesheretofore encountered in the hydration of water imbibing materials suchas cellulose ethers.

It is another object of this invention to provide a rapid and convenientmethod for effectively hydrating a cellulosic material.

It is a further object of the invention to provide a method forpreparing cellulosic slurries which can be easily admixed withsubstantial amounts of water which may contain various other ingredientsto provide a uniform lump-free dispersion of the cellulosic material.

These and other related objects are achieved by a process for hydratinga cellulose ether which comprises wetting the cellulose ether with aneffective amount of a soap-forming fatty acid or mixture of fatty acidswhich is immiscible with water and which is liquid at about roomtemperature to form a cellulosic slurry which can be added directly towater or to an aqueous formulation containing other conventionaldetergent components. The resulting aqueous admixture is then agitatedto form a uniform, smooth, stable, lump-free, aqueous dispersion. Thestep of wetting the cellulosic material with a suitable fatty acid priorto mixing with water can be conveniently described as prewetting thecellulosic with the fatty acid.

The term effective amount refers to an amount of wetting agent which issufficient to wet the cellulose ether to such a degree that it can beeasily and completely hydrated to provide a smooth, lump-freedispersion.

By hydrating cellulose ethers in accordance with the process of thepresent invention, the costly and time consuming heating and coolingcycles of the hot water method are not necessary. Moreover, in theprocess of the present invention wetting agents are employed which arenot miscible with water as has been true of the previously employedwetting agents, such as methyl alcohol, ethyl alcohol, and glycerol.This is indeed quite unusual, since one would ordinarily expect that inorder to disperse the cellulose ethers in water by a prewettingtechnique, the wetting agent should be miscible with or dispersible inwater.

In general, the present process is applicable to the production of anyaqueous composition, e.g., a detergent composition, containing acellulose ether in the formulation. While it is preferred, for bestresults, to add the wetted cellulosic material to water alone therebyforming a uniform slurry prior to the addition of any other ingredientssuch as detergent components, the order of addition of the ingredientsis not critical. Thus, for example, the cellulose other which has beenwetted with a soapforming fatty acid which is pourable at roomtemperature can be added to an aqueous composition containing at leastsome of the detergent components and this composition agitated toproduce a uniform, smooth formulation to which any of the balance of theingredients of the complete detergent formulation may be added, thusproducing a smooth uniform lump-free dispersion. Accordingly, the termaqueous formulation, as used herein, is intended to include compositionscomprising water and some or all of the other ingredients of the finalformulation, as well as water alone. Alternatively, some or all of theingredients of the detergent formulation can be admixed with the wettedcellulosic material and this mixture can then be mixed with water toform the final formulation. Regardless of the order in which the variousadditives are mixed with the fatty acid-wetted cellulosic material, thefinal product is a smooth, uniform, stable, lumpfree, aqueous detergentcomposition.

The term detergent formulation components as used herein is intended toinclude any and all of the usual ingredients commonly found in detergentformulations. Such components include the well known organic detergentsof the anionic, cationic, nonionic and ampholytic classes, e.g., alkylsulfonates, sulfated alcohols, fatty acid salts, alkylbenzenesulfonates, quaternary ammonium compounds, polyethylene oxidecondensates of fatty acids, aliphatic alcohols, aromatic alcohols, andthe like.

The wetting of the cellulose ether with the fatty acid can beaccomplished at about room temperature (about 'F.) or if desired at theelevated temperatures usually encountered in manufacturing plants e.g.,up to about F. In general, the amounts of the reagents employed areabout one part of cellulose ether to at least about 0.70 part andpreferably about one part, of fatty acid and about sixteen to abouteighty parts and preferably about thirty parts of water. The agitationperiod is about five minutes at relatively high stirrer speeds.

The fatty acids suitable for use in the practice of this inventioninclude any aliphatic monocarboxylic acid or mixtures thereof which isimmiscible and nondispersible in water and which can be saponified toyield a watersoluble soap. The fatty acids which may be straight orPatented June 27, 1967- branched chain can be derived from naturalsources or may be prepared synthetically, e.g., from alpha olefins. Theterm liquid at room temperature refers to material having the ability towet a solid at that temperature. This characteristic is generallyrecognized by the existence of a pourablc liquid phase. Generally, thepreferred fatty acids having the ability to wet cellulose ethers at roomtemperature are those acids containing from to 22 carbon atoms which areimmiscible and nondispersible in water. Suitable acids include oleicacid, coconut oil fatty acids, palmitoleic acid, linoleic acid,linolenic acid, ricinoleic acid, and the like as well as mixtures offatty acids which individually may be solid at room temperature but incombination have a liquid phase capable of wetting the cellulosicmaterial. Illustrative mixtures of fatty acids which are liquid at roomtemperature, include mixtures of capric acid and lauric acid (e.g., 80%capric, lauric), mixtures of capric acid and myristic acid (e.g., 80%capric, 20% myristic), mixtures of capric acid and oleic acid (e.g., a1:1 mixture), mixtures of palmitic acid and capric acid (e.g., 10%palmitic and 90% capric), and certain mixtures of oleic acid withstearic acid or palmitic acid. The above percentages are by weight.Additional suitable fatty acids are the mixed acids obtained fromnaturally occurring oils such as cod liver oil, shark oil, seal oil,perilla oil, linseed oil, candlenut oil, hempseed oil, walnut oil,poppyseed oil, sunflowerseed oil, maize oil, rapeseed oil, mustardseedoil, apricot kernel oil, almond oil, castor oil and olive oil.Accordingly the term fatty acid as used herein, is intended to includeboth single fatty acids and mixtures of fatty acids, as describedherein.

A particularly important advantage obtained by using soap-forming fattyacids as wetting agents for the cellulosic material is that these agentscan be saponified and converted to water-solublesoaps by treatment withan alkali. Thus, the wetting agent of the invention can be converted toa material which becomes a useful and integral part of the detergentcomposition unlike other known wetting agents which tend to separate outfrom the detergent composition thus rendering it unsightly to the user.Such incompatible wetting agents act as diluents to decrease the cost ofthe formulation and also decrease its effectiveness.

In addition to the detergents themselves, the formulations may containother substances whichare adjuvants and additives such as builders,e.g., tripolyphosphates, pyrophosphates, sodium hexametaphosphate,sodium trimetaphosphate, alkali metals (e.g., sodium and potassium)carbonates, borates, silicates, persulfates, perborates percarbonates,and the like, bleaching agents of the oxygen-releasing andchlorine-releasing types e.g., the hypochlorites, and potassium andsodium dichlorocyanurate, trichlorocyanuric acid, chlorinated trisodiumphosphate, dichloro-dimethylhydantoin, n-chlorosuccinimide,chloroamine-T, and the like, and germicides such as hexachlorophene, andthe halogenated salicylani lides, e.g., 3,S-dibromosalicylanilide,3,4,S-tribromosalicylanilide and the like.

The compositions may also contain optical brighteners, dyes, fillers,e.g., sodium chloride, sodium sulfate, and the like, emollients, skinconditioners and other suitable adjuvants.

The cellulose ether may be used alone or mixed with another celluloseether. Typical examples thereof are a methylcellulose, e.g., one having27.532% methoxyl groups per cellulose molecule; an ethylcellulose, e.g.,one having 0.65 mole of ethoxyl groups per anhydroglucose unit; a sodiumcarboxymethylcellulose, e.g., one having 0.7 mole of carboxymethylgroups per anhydroglucose unit; a sodium carboxymethylmethylcellulose,e.g., one having 0.150.2 mole of carboxymethyl groups per anhydroglucoseunit and 14-22% of methoxyl groups per cellulose molecule; a sodiumcarboxymethylethylcellulose, e.g., one having 0.1 mole of carboxymethylgroups and 1.0 mole of ethoxyl groups per anhydroglucose unit;

and a sodium carboxymethylhydroxyethylcellulose, e.g., one having 0.34mole of carboxymethyl groups and 0.76 mole of hydroxyethyl groups peranhydroglucose unit.

Example 1 A mixture of 1.25 grams of sodium carboxymethylcellulosehaving 0.7 mole of carboxymethyl groups per anhydroglucose unit (120high% active) and 3.4 grams of methylcellulose (viscosity 25 centipoisesas measured in a 2% aqueous dispersion) having 27.5-32% methoxyl groupsper cellulose molecule was prewetted with 5 grams of coconut oil fattyacids at room temperature (75 F.). The resulting cellulosic slurry wasthen added to 144.5 grams of water at room temperature under rapidmechanical stirring. After 5 minutes the stirring was stopped and thedispersion observed for undissolved flecks of cellulosic gel. Thedispersion was again observed after 2.5 hours and 24 hours of furtherstanding with no additional stirring. The observations are set forthbelow.

Flecks of undispersed gel remaining after:

5 minutes few 2.5 hours practically none 24 hours none Example 2 Fivegram samples of (a) methyl cellulose of 4000 centipoise viscosity (in 2%aqueous dispersion) having from 27.5 to 32% methoxyl groups percellulose molecule (Methocel NF 4000 cps.) and of (b) sodiumcarboxymethylmethylcellulose (of low viscosity measured in a 2% aqueousdispersion) having 0.2 mole of carboxymethyl groups and 1.0 mole ofmethoxyl groups per anhydroglucose unit were wetted with 5 gram portionsof coconut oil fatty acids, and the resulting slurry added to water asdescribed in Example 1, above. The aqueous dispersion was then examinedas in Example 1 for undispersed cellulosic material. The results are setforth below.

Flecks of undispersed gel remaining after:

5 minutes Considerable 2.5 hours none 24 hours none Example 3 Variousfatty acid wetting agents were used to prewet cellulosic materialsdescribed below, following the procedure outlined in Example 1, above.The amount of each wetting agent, the composition of the cellulosicmaterials and the results obtained are set forth in Table I, below.

TABLE I Flecks of Undispersed Cellulose Ether After- 5 minutes 2.5 hours24 hours (:1) Coconut Oil Fatty Acids (5.0 None None"... None.

g.)As wetting agent for: 5.0 g. CMtZ (b) ()leic Acid (5.0 g.)As wetdo.do D0.

ting agent for: 5.0 g. CMC. (c) ()leic Acid (5.0 g.)As wet ting agentfor mixture of:

1.25 g. CMIIEC 2 v s A "do (l0 D0. 3.40 g. Methocel t do d0 Do. 1) lcicAcid (5.0 g.)-As Wetting agent for:

1.25 g. CMEC 3 Practically do Do.

none. 3.40 g. Methocel 4 1 CMCsodium cnrboxymethylcellulose (technicalgrade) having 0.7 mole of carboxymethyl groups per anhydroglucose unit.

2 C M HE (7-s0dium carboxymethylhydroxyethylcellulose.

l CNlEC smlium carboxymethylethylcellulose having 0.1 mole ofcarboxymethyl groups and 1.0 mole of ethyl groups per anhydroglucoseUlll 4 \lcthylcclluloseMethocel containing 27% methoxyl groups perccllulosc molecule.

Example 4 The fatty acid wetting process was effectively applied to thefollowing detergent compositions.

Percent Carboxymethylcellulose technical grade, 0.7

degree of substitution 0.25 Methylcellulose (Methoceh 0.68 Coconut oilfatty acids 1.00 Sodium xylenesulfonate 2.17 Dodecylbenzene sulfonicacid 2.04 Sodium tallow methyltaurate 3.61

The condensation product of one mole of lauric monoethanol'amide withone mole of ethylene oxide 1.00 Triethanolamine 1.00 Tetrapotassiumpyrophosphate 25.00 Sodium silicate (2.5 ratio) 3.10 Water, potassiumhydroxide (to pH 11.8) and miscellaneous impurities 60.15

1 SiOeZ N320.

TABLE II Detergent composition prepared by acid ing cellulosic-fattyacid to following Brookfield viscosity (cps) Spindle N0. 2,

components at room temperature: 6 r.p.n1. 75 F.

(1) Water 520 (2) Water, potassium hydroxide 320 (3) Water, potassiumhydroxide dodecylbenzene sulfonic acid (4) Water, potassium hydroxidedodecylbenzene sulfonic acid, sodium xylenesulfonate (5) Control(cellulosics hydrated by hot-watermethod) (6) Water, potassiumhydroxide, dodecylbenzene sulfonic acid, sodium xylenesulfonate added tocellulosics wetted with coconut oil fatty acids (reverse of No. 4) 288In general, the higher the viscosity of the dispersion, the morecomplete is the hydration of the cellulosic and the more stable is thedetergent formulation. Since the maximum viscosity and the most stableformulations are obtained by adding the cellulosic slurry to the watercomponent alone, this is the preferred method. In each case, however,the dispersion prepared by the process of the instant invention had ahigher viscosity than that obtained by hydration via the hot-watermethod.

Example 5 The following anionic and nonionic liquid detergentformulations were prepared by the method of this invention in which thecellulosic material was wetted with the fatty acid wetting agent at roomtemperature to form a slurry which was then admixed with water to form adispersion into which the balance of the ingredients were incorporatedto provide a smooth uniform lumpfree dispersion.

I. ANIONIC DETERGENT ACTIVES Percent active basis CarboxymethylcelluloseCT, 70 low 0.218 Methocel (R) 0.511 Oleic acid 0.753 Water 15.00 Sodiumxylene/toluene sulfonate 7.930 Dodecylbenzene sulfonic acid 8.660Potassium hydroxide 3.100 Laurie isopropanolamide 3.110 Tetrapotassiumpyrophosphate 18.580 Sodium silicate (2.5 ratio) 2.520

Water, miscellaneous impurities, potassium hydroxide to pH 12.1 36.948

1 SiOz: M120. 1()() Percent active basis Carboxymethylcellulose CT, 70low 0.153 Methocel 0.567 Coconut oil fatty acids 1.200 Water 15.000Sodium xylenesulfonate 8.150 T riethanolamine 1.500 Lauriediethanolamide 4.000 Sodium laurylsulfa-te 8.000 Tetrapotassiumpyrophosphate 15.000 Sodium silicate (2.5 ratio) 7.000 Water,miscellaneous impurities, potassium hydroxide to pH 12.0 39.430

1 S102 NaaO. 10 0.000

II. NONIONIC DETERGENT ACTIVES Percent active basisCarboxymethylhydroxyethylcellulose 0.50 Rapeseed fatty acids 1.00 Water39.68 Sodium alginate (P'rotanol SF, 100 mesh) 1.07 T-riethanolamine1.00 Dimethyl dodecylamine oxide 10.00 Tetrapotassium pyrophosphate18.00 Sodium silicate (2.5 ratio) 6.00 Water, miscellaneous impurities22.75

Potassium hydroxide to pH 10.7 100.00

A liquid detergent composition may be prepared as shown in Example 5(a),above substituting a 1:1 mixture of capric acid and oleic acid for theoleic acid shown therein.

Example 6 A liquid detergent composition is prepared by wetting one partby weight of sodium carboxymethyl cellulose with 0.7 part by weight ofricinoleic acid at a temperature of 70 F. The resulting slurry is thenadded to 25 parts by weight of water containing 5 parts by weight of thecondensate of 1 mole of the ammonium salt of a mixture of sulfated fattyalcohols (myristyl and lauryl in a ratio of 2:1) with 3 moles ofethylene oxide. The product is a smooth uniform lump-free dispersion.

Example 7 Four grams of sodium carboxymethylcellulose were pre-wettedwith 4 grams of linoleic acid at room temperature. The resulting slurrywas added to grams of water and stirred to provide a homogeneousemulsion which was free of flecks of undispersed gel.

It will be appreciated that various modifications and variations may bemade in the process of the present invention without departing from thespirit thereof; accordingly, the process of this invention is to belimited only by the scope of the appended claims.

What is claimed is:

1. In a process for preparing organic detergent formulations containingwater and a cellulose ether, the improvement which comprises forming acellulosic slurry by prewetting the cellulose ethe-r with an effectiveamount of at least one soap-forming aliphatic monocarboxylic fatty acidhaving from to 22 carbon atoms, said fatty acid being liquid at roomtemperature and immiscible and nondispersible in water.

2. A process as described in claim 1 for preparing aqueous detergentcompositions wherein the effective amount of the fatty acid is at leastabout 0.70 part by weight per part of cellulose ether.

3. A process as described in claim 2 wherein the cellulose ether isprewetted with at least about 0.70 part by weight of fatty acid per partof cellulose ether to form a cellulosic slurry, admixing the slurry withfrom about 16 to about 80 parts of water to form a smooth stablelump-free dispersion.

4. A process as defined in claim 1 wherein the fatty acid is oleic acid.

5. A process as defined in claim 1 wherein the fatty acid is ricinoleicacid.

6. A process as defined in claim 1 wherein the fatty acid is palmitoleicacid.

7. A process as defined in claim 1 wherein the fatty acid is a mixtureof fatty acids, said mixture being liquid at about room temperature.

8. A process as defined in claim 7 wherein the mixture of fatty acidsconsists essentially of capric acid and lauric acid.

9. A process as defined in claim 7 wherein the mixture of fatty acidsconsists essentially of palmitic acid and myristic acid.

10. A process as defined in claim 7 wherein the mixture of fatty acidsconsists essentially of capric acid and oleic acid.

11. A process as defined in claim 7 wherein the fatty acid is coconutoil fatty acids.

12. A process as defined in claim 7 wherein the fatty acid is rapeseedfatty acids.

13. A process as defined in claim 7 wherein the fatty acid is a mixtureconsisting essentially of percent by weight capric acid and 20 percentby weight lauric acid.

14. A process as defined in claim 7 wherein the fatty acid is a mixtureconsisting essentially of about 80 weight percent capric acid and about20 weight percent myristic acid.

15. A process as defined in claim 7 wherein the fatty acid is a mixtureconsisting essentially of about weight percent palmitic acid and about10 weight percent capric acid.

No references cited.

LEON D. ROSDOL, Primary Examiner.

ALBERT T. MEYERS, Examiner.

W. E. SCHULZ, Assistant Examiner.

1. IN A PROCESS FOR PREPARING ORGANIC DETERGENT FORMULATIONS CONTAININGWATER AND A CELLULOSE ETHER, THE IMPROVEMENT WHICH COMPRISES FORMING ACELLULOSIC SLURRY BY PREWETTING THE CELLULOSE ETHER WITH AN EFFECTIVEAMOUNT OF AT LEAST ONE SOAP-FORMING ALIPHATIC MONOCARBOXYLIC FATTY ACIDHAVING FROM 10 TO 22 CARBON ATOMS, SAID FATTY ACID BEING LIQUID AT ROOMTEMPERATURE AND IMMISCIBLE AND NONDISPERSIBLE IN WATER.